Reinforced diaphragm valve

ABSTRACT

A reinforced plastic valve apparatus in a preferred embodiment comprises an upper valve portion, a lower valve portion, an endoskeletal structure configured as a weir support or reinforcing member and an exoskeletal framework configured as a support collar. The upper valve portion preferably includes an upper plastic valve housing or body, a resilient diaphragm and a valve actuator. The lower valve portion comprises a lower plastic valve housing or body that is preferably configured to mate with the upper valve housing to define a valve interior. The lower valve body preferably has an integral weir which, in conjunction with the resilient diaphragm, defines a fluid passage. The diaphragm is configured to sealingly engage and disengage with the weir as effected by the valve actuator. The weir support member is disposable within the lower housing to support the weir.

RELATED APPLICATION INFORMATION

This application claims benefit of U.S. Provisional Application No.60/276,658, filed on Mar. 16, 2001.

FIELD OF THE INVENTION

The present invention relates to valves, and more particularly, toplastic diaphragm valves having a weir-type seating surface.

BACKGROUND OF THE INVENTION

Diaphragm valves provide excellent sealing and isolation characteristicsto contain fluid being controlled and prevent migration of thecontrolled fluid into the valve mechanisms or out of the valve.Diaphragm valves utilize a resilient diaphragm and a valve shoulder toengage a valve seat and prevent the flow of fluid past the valve seat. Aweir-type diaphragm valve is a valve utilizing a resilient diaphragmthat engages a weir to control flow of fluid over the weir. Thediaphragm may be controllably lifted and sealed against the weir toselectively permit flow through the valve.

Weir-type diaphragm valves are often employed in the biotechnological,pharmaceutical, chemical, food processing, beverage, cosmetic, andsemiconductor industries. These industries often require valves thatprotect against product contamination and leakage within the valve,workplace and atmosphere. Weir-type diaphragm valves are well suited tomeet these requirements because the mechanical valve parts are isolatedfrom fluid flowing through the valve.

Traditionally, diaphragm valves were made of metal alloys. Such metalvalves provide good durability and service life in basic fluid controlapplications. However, metal alloys are not well suited to some processenvironments, such as pharmaceutical and semiconductor manufacturing. Inthose applications, the fluids often used are highly corrosive orcaustic and also must be kept ultra pure. These corrosive fluids canerode the metal from the valve body and contaminate the ultra pureprocess fluids. Also, some metal alloys may act as catalysts causing theprocess fluids to undergo chemical reactions, thereby compromising endproducts, and potentially, worker safety.

Specialized high strength alloys and stainless steels have beendeveloped to minimize reactivity and erosion in the valve bodies.However, such specialized alloys are very difficult to cast or machineinto valve components. The resulting valves are very costly to purchaserelative to traditional metal valves. Moreover, stainless steel is notsuitable in particular applications such as the semiconductor processingindustry.

Plastic lined metal valves were developed to allow traditional metalvalve bodies to handle caustic fluids in specialized processapplications. The metal valve body is first formed by casting ormachining. Then, a plastic or fluoropolymer is molded in the interior ofthe valve body where process fluids contact the body. U.S. Pat. No.4,538,638 discloses a plastic lined metal bodied diaphragm valve.

Although, the plastic lined metal valves and plastic lined plasticvalves may provide the desired resistance to degradation by processfluids, manufacturing costs are high. High costs are attributable to thecomplicated multi-step manufacturing process of molding a plastic liningin a support body. The plastic lining may be subject to creep withrespect to its surface underneath. Creep reduces the useful life of theexpensive plastic lined valve.

Through advances in plastics and manufacturing technologies, valves madeentirely or almost entirely of fluoropolymers have become commerciallyviable. Such plastic valves are capable of providing a cost effectivevalve having desirable non-reactive and corrosive resistant propertiesideally suited for use in pharmaceutical and semiconductor manufacturingapplications. U.S. Pat. Nos. 5,279,328 and 4,977,929 disclose plasticdiaphragm valves. In certain applications, plastic bodied valves mayalso be provided with a plastic lining. U.S. Pat. No. 4,538,638discloses a plastic lined diaphragm valve.

While fluoropolymer valves and plastic valves having fluoropolymerliners are well suited to withstanding caustic fluids, they aresusceptible to dimensional degradation such as warpage and creep. Fluidsused in industrial processes, such as the pharmaceutical, sanitary, andsemiconductor industries, generally require the process fluids to bekept ultra pure. Components used in fluid delivery systems, such asvalves, are routinely cleansed to ensure that contaminants do not becometrapped in such components and thereby introduced into the processsystem.

The cleansing processes may involve exposure to high temperature steamfor a sufficient amount of time to sterilize the component. Particularlywhen repeated numerous times, this sterilization process can cause theplastic in the valve to change dimension slightly, resulting in warpage.Creeping results when plastic is subject to stress over a period oftime. The plastic component's dimensions can change from the stress. Dueto such warpage and creep, tolerances, especially at the weir, areaffected and leakage may result. Therefore, a need exists to provide aplastic lined weir-type diaphragm valve that has improved dimensionalstability when exposed to repeated cleansing operations or exposure toconditions normally conducive to warpage or creep.

SUMMARY OF THE INVENTION

A reinforced plastic valve apparatus in a preferred embodiment comprisesan upper valve portion, a lower valve portion, an endoskeletal structureconfigured as a weir support or reinforcing member and an exoskeletalframework configured as a support collar. The upper valve portionpreferably includes an upper plastic valve housing or body, a resilientdiaphragm and a valve actuator. The lower valve portion comprises alower plastic valve housing or body that is preferably configured tomate with the upper valve housing to define a valve interior. The lowervalve body preferably has an integral weir which, in conjunction withthe resilient diaphragm, defines a fluid passage. The diaphragm isconfigured to sealingly engage and disengage with the weir as effectedby the valve actuator. The weir support member is disposable within thelower housing to support the weir. In preferred embodiments, anexoskeletal framework configured as the support collar extendscircumferentially around the valve and supports the weir support member.In particular embodiments, the valve body components may also comprise aplastic fluoropolymer lining for contacting fluids. The invention alsoincludes the method of manufacturing a reinforced plastic valvepreferably including the step of providing a rigid support member to theweir of a lower valve housing.

A plastic diaphragm valve apparatus may comprise an upper valve housing,the upper housing including a resilient diaphragm and means foractuating the diaphragm; a lower valve housing configured to mate withthe upper housing, the lower housing having an interior defining a fluidpassage and a weir, the weir configured to sealingly contact todiaphragm; and means for supporting the weir. The plastic diaphragm mayfurther comprises means for supporting a portion of the upper and lowerhousings, said housing support means secured to the upper and lowerhousings.

An object and advantage of particular embodiments of the presentinvention is to provide a plastic diaphragm valve with improveddimensional resilience and a method of manufacturing such a valve.

Another object and advantage of particular embodiments of the presentinvention is to provide for a fluoropolymer diaphragm valve that isdimensionally tolerant to repeated sterilization processes.

Another object and advantage of particular embodiments of the presentinvention is to provide for a valve that is able to withstand repeatedsterilization processes and that is also suitable to use in thepharmaceutical, biotechnological, chemical, and/or semiconductorindustries.

Another object and advantage of particular embodiments of the presentinvention is to provide a means for reinforcing a plastic valve.

Another object and advantage of particular embodiments of the presentinvention is to provide for a method of reinforcing a plastic valve,thereby having improved resistance to warpage and creapage.

Another object and advantage of particular embodiments of the presentinvention is to provide a support for the weir of a plastic valve.

Further features, objects and advantages of the present invention willbecome apparent to those skilled in the art in the detailed descriptionbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded parts view of a diaphragm valve according to anembodiment of the present invention.

FIG. 2 is a perspective view of the assembled diaphragm valve of FIG. 1.

FIG. 3a is a cross sectional view of a portion of the reinforceddiaphragm valve according to an embodiment of the present invention.

FIG. 3b is a cross sectional view of a portion of the reinforceddiaphragm valve of FIG. 3a taken at line 3 b—3 b.

FIG. 4 is a side view of the weir support member according to oneembodiment of the present invention.

FIG. 5 is a side view of the weir support member of FIG. 4 engaging thesupport collar.

FIG. 6 is a cross sectional view of a lined plastic diaphragm valveaccording to an embodiment of the present invention.

FIG. 7 is a cross sectional view of a portion of a reinforced diaphragmvalve according to an embodiment of the present invention.

FIG. 8 is a perspective view of a reinforced diaphragm valve having areinforcing framework according to an embodiment of the presentinvention.

FIG. 9 is an exploded parts view of the reinforced diaphragm valve ofFIG. 8.

FIG. 10 is a cross sectional view of a portion of the reinforceddiaphragm valve of FIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A reinforced weir valve 10 in accordance with the invention isillustrated and generally comprises an upper valve portion 12, a lowervalve portion 14, a reinforcing exoskeletal framework 20 and anendoskeletal support member 22 configured as a valve seat reinforcingmember. The valve has a valve body 24 or housing, an actuator 25, avalve member 26 and valve seat 30. In the preferred embodimentillustrated, the valve 10 is a diaphragm valve and the valve bodycomprises a plastic upper valve housing or body 50 and a plastic lowervalve body 52. The upper valve body 50 has an actuator housing 54 withactuation connection means 56, for example, pneumatic line connectors.Connected to the actuator housing 54 is an upper valve housing 72 and anupper flange 58 with a plurality of upper mounting holes 62.

The lower valve body 52 has a lower flange 60 with a plurality of lowermounting holes 64 and mounting slots 65. The lower valve body 52 has afluid passageway 74 extending through an open interior 71 of the body 52with a pair of inlet/outlets 75. A seating surface 76 is located withinthe lower valve body 52 and also within the fluid passageway 74. Theseating surface is part of the valve seat 30 configured as a weir, whichspans the open interior 71. The seating surface 76 is sized to cooperatewith the diaphragm 104 and the actuator 106 to form a fluid tight sealat the weir 78. The lower valve body 52 further includes an aperture 80that extends from the exterior 53 of the lower valve body 52. Theaperture 80 preferably forms a bore 81 that begins at the exterior 53 ofthe lower valve body 52 and extends through at least the length of theseating surface 76. The length of the bore 81 extends through the weir78 and is not exposed to the fluid passageway 74.

The valve is reinforced, or supported, by the provision of theendoskeletal support member 22 and is configured as a weir supportmember 82 and the exoskeletal framework 20 configured as support collar90. The weir support member 82, as shown in FIG. 4, is preferably rodshaped having a first end 86, a second end 88, a longitudinal surface 87and notches 84 in the longitudinal surface 87 at both ends 86, 88. Asshown in FIG. 7, the weir support member 82 may also be any suitablyshaped elongated member. Those skilled in the art will recognize thatmany alternative embodiments of weir support member shape, such aspolygonal, will provide the envisioned support without departing fromthe scope of the present invention.

The support collar 90, shown in FIGS. 1 and 5, comprises an upperportion 92 and a lower portion 94. The upper portion 92 and lowerportions 94 are preferably approximately U-shaped and overlap whenplaced on the valve housing. There are a plurality of collar mountingholes 96 and slotted mount holes 97 in the upper portion 92 thatcorrespond to respective upper mounting holes 62, lower mounting holes64 and mounting slots 65. The slotted mount holes 97 aide in joining theupper portion 92 to the lower portion 94 and the valve bodies 50, 52during assembly.

The lower portion 94 may be provided with two mounting posts 98 thatcooperate with the mounting slots 65 and upper mounting holes 62 of thevalve bodies 50, 52 and slotted mount holes 97 of the upper portion 92for enabling the joining of the valve bodies 50, 52. The mounting posts98 have a threaded portion 100 and a smooth portion 102 to provide ameans for fastening the valve bodies 50, 52 together. The lower portion94 also has two collar mounting holes 96 that communicate withrespective collar mount holes 96 of the upper portion 92, the uppermounting holes 62 of the upper valve body 50 and the lower mountingholes 64 of the lower valve body 52.

Referring to FIG. 3a, the diaphragm valve has a diaphragm 104 in adisengaged position. The compressor 106 is configured to providepressure on the diaphragm 104 when called to close the fluid passageway74. The compressor 106 shown is a partial hemispherical type compressorthat has a similar cross section through 360 degrees of rotation. FIG. 7shows a blade-type actuator 107 that is an alternative to the partialhemispherical actuator of FIG. 3. The blade type actuator 107 spans thelength of the weir 78 and has a width approximately equal to the weir78. Those skilled in the art will recognize that other embodiments ofthe actuator 106 are functionally equivalent to those depicted anddescribed herein without departing from the scope of the invention.

The compressor 106 is moved by a drive means as in the actuator 25 suchas a pneumatic means, electric means, or manual means. U.S. Pat. Nos.4,977,929, 6,056,264, 5,368,452 and 5,279,328 disclose several suitabledrive means for actuators used in weir-type diaphragm valves. U.S. Pat.Nos. 4,977,929, 6,056,264 and 5,368,452 are hereby incorporated byreference.

The diaphragm valve of the present invention can utilize many differenttypes of fittings 108, 138 to join the valve to pipe and piping systems.FIG. 1 shows an Entegris PureBond® fitting. FIG. 6 shows an EntegrisSynergy® type sanitary fitting that utilizes an overmolded plasticportion on the fittings. Entegris Flaretek® fittings are also suitableto the present invention. These marks are all registered to Entegris,Inc. the owner of the instant application. U.S. Pat. Nos. 4,848,802,4,929,293, 5,472,244 and 5,837,180 all disclose examples of suitablefittings for coupling a plastic valve to tubing. These four patents areincorporated herein by reference. Other fittings also may be suitable.

Referring to FIG. 4, a side view of the weir support member 82 is shown.

Referring to FIG. 5, the weir support member 82 is shown in cooperationwith the support collar 90. The notch 84 seats on the upper portion 92to support the weir support member 82 and retaining the member in theaperture 80 in the lower body. The overlapping portion 92, 94 provideuniform support at the bottom surface 117 of the flange 60 and allow thecollar to be the function equivalent of a unitary collar. Theoverlapping configuration allows the compression of the upper and lowervalve bodies as provided by each of the bolts 66 or studs 68 to act on alarge area of the flanges. The cooperation of the weir support member 82and the support collar 90 provide support and reinforcement to the weir78, the valve flanges, and generally, the valve bodies 50, 52. Thus,warpage and creep of the weir, the flanges and generally the valvebodies is inhibited.

Referring to FIG. 6, an alternative embodiment of the present inventionis illustrated. A plastic valve body 126 is provided with a plasticfluoropolymer lining 125. The valve body 126 has a weir 136 and a weirbase portion 134. A weir support member 142 contacts the weir baseportion 134 and the plastic lining 125, thereby supporting the weir 136.The support collar 130 engages the mounting flange 140 of the valve body126. The lining 125 terminates in fittings 138 for attachment to pipe orpiping systems. The fitting 138 of FIG. 6 includes a support ring 139.Valve body 126 is adapted to receive an upper valve body 50 such as thatshown in FIG. 1 and described herein.

The valve bodies 50 and 52 are preferably formed of fluoroploymers,including but not limited to perfluoroalkoxy resin (PFA), polyvinylidenefluoride (PVDF) or other fluoropolymers. In certain applications, otherplastics may be suitable, such as polyvinyl chloride (PVC), orpolypropylene (PP). The body components are preferably injection molded,although they may be machined. The wetted portion of the diaphragm 104may be formed of polytetrafluoroethylene (PTFE). The diaphragm may becomposite with a layer adjacent the PTFE layer formed of EPDM. The weirsupport member 82 and the support collar 90 are preferably constructedof stainless steel. Stainless steel provides the desirable amount ofrigidity and durability to provide the plastic valve with the desiredamount of dimensional integrity. In certain instances, other rigidmaterials such as carbon fiber filled PEEK or other polymers may beutilized. Those skilled in the art will recognize that the abovestructures may be constructed from other materials without departingfrom the scope of the invention.

The reinforced valve according to one embodiment of the presentinvention is assembled as shown in the assembly drawing of FIG. 1,resulting in the completed valve of FIG. 2. The weir support member 82is first inserted into the aperture 80 so that the notches 84 face awayfrom the lower flange 60. The lower portion 94 of the support collar 90is next disposed about the lower flange 60 on the lower valve body 52 sothat the collar mount holes 96 align with the lower mounting holes 64.Next, the upper portion 92 is inserted into the space between the lowerportion 94 and the lower flange 60. The slotted mount holes 97 engagethe mounting posts 98 when the collar mount holes 96 align with thelower mounting holes 64 and the collar mount holes 96 of the lowerportion 94.

The upper valve body 50 is next placed onto the assembled lower valvebody 52. Two of the upper mounting holes 62 receive the mounting posts98 and the remaining upper mounting holes 62 are aligned with respectivemounting holes 64 and 96. When the upper flange 58 is in contact withthe lower flange 60, the threaded portions 100 of the mounting posts 98will protrude from the upper mounting holes 62 in the upper flange 58. Aplurality of washers 68 are placed over the threaded portions 100 and anut 70 is tightened onto each of the exposed threaded portions 100.Finally, bolts 66, or other suitable fastener, receive a plurality ofwashers 68 and are inserted though the remaining aligned mounting holes96, 64, 62 and tightened. Preferably the diaphragm housing is providedwith threaded bores to receive the bolts 66.

In operation, the diaphragm 104 confronts valve seating surface 76 andmoves by the actuator 25 including the compressor 106. The diaphragm 104approaches the seating surface 76 until a seal is formed by engagementwith the seating surface 76. Such sealing creates a fluid tightseparation of the fluid flow between the halves of the valve bodydefined by the weir 78. The valve is opened by displacing the diaphragm104 from the seating surface 76 and the weir 78.

Referring to FIGS. 8, 9 and 10, a further embodiment of a valve 158 isillustrated. This embodiment similarity has a valve body 160 comprisedof an upper valve body portion 162 and a lower valve body portion 164.The lower valve body portion has an integral weir 168, a first flow duct172 with a first flow passage 173, a second flow duct 174 with a secondflow passage 175, and a third flow duct 176 with a third flow passage177. The first and second flow ducts are contiguous and collinear andtogether with the lower valve body define a central flow passage 180that has a central flow passage axis A₁. Said central flow passageconnects to fourth flow passage extending along one face 184 of the weir168, to the open interior 185 above the weir where the diaphragm moves.A fifth flow passage 188 connects to the third flow passage 177 andextends up to the other face 190 of the weir to the open interior 185above the weir

The weir has a central axis A₂ centrally located through said weir. Saidweir axis A₂ is preferably coaxial with an actuator axis A₃ and a valveaxis A₄. The actuator will typically have a pneumatic cylinder or manualrotatable shaft that defines said actuator axis. The third flow duct andthird flow passage have a third flow passage or duct axis A₅. Theactuator axis A3, valve axis A₄, and weir axis A₂ are displaced from andat preferably a right angle to the central flow duct axis A₁.

The valve 158 of FIGS. 8, 9 and 10 has reinforcing framework 198comprising an exoskeleton framework 200. The exoskeleton frameworkcomprises a flange support ring 206, a lower valve body support plate208. The flange support ring 206 has two U-shaped segments 212, 214. TheU-shaped segments overlap to define a ring portion that engages theflange 217 of the lower valve body 164.

In the embodiment of FIGS. 8, 9 and 10, five bolts 224 extend throughapertures 226 in the lower plate 208, through the lower valve bodyportion 164 and into threaded holes 168 in the flange support ring 206.Additional bolts 230 extend through the flange retainer ring through thelower valve body flange 217, through the diaphragm flange 234, throughthe upper valve body portion 162 and attach to nuts 238. A furthermounting bracket 244 may be utilized to attach the flange ring 206 to asuitable mounting surface.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize changesmay be made in form and detail without departing from the spirit andscope of the invention.

What is claimed is:
 1. A diaphragm valve apparatus comprising: an uppervalve body containing an actuator, a resilient diaphragm; a lower valvebody configured to mate with the upper valve body, the lower valve bodyhaving an interior defining a fluid passage, the lower valve bodycomprising an integral weir, the weir configured to sealingly contactthe diaphragm; a weir support member extending longitudinally throughthe weir for reinforcing said weir; and a support collar secured to boththe upper housing and lower housing, the support collar engaged with theweir support member.
 2. The apparatus of claim 1, wherein the supportcollar comprises a U-shaped upper portion; and a U-shaped lower portion,the two portions overlapping and forming a closed loop and extendingaround the lower valve body.
 3. The apparatus of claim 1, wherein thesupport collar is constructed of stainless steel.
 4. The apparatus ofclaim 1, wherein the weir support further comprise a first and secondend and at least one of said first and second ends having a notchtherein for engaging with the support collar.
 5. The apparatus of claim1, wherein the plastic upper valve body contains the resilientdiaphragm.
 6. The apparatus of claim 5, wherein the resilient diaphragmis an integral part of the plastic upper valve body.
 7. The apparatus ofclaim 1, wherein the upper valve body and the lower valve body areplastic.
 8. A diaphragm valve apparatus comprising: an upper valvehousing, the upper housing including means for actuating the diaphragm;a resilient diaphragm; a lower valve housing configured to mate with theupper housing, the lower housing having an interior defining a fluidpassage and a weir, the weir configured to sealingly contact thediaphragm; means for supporting the weir; and a support collar securedto both the upper housing and lower housing, the support collar engagedwith the means for supporting the weir.
 9. The apparatus of claim 8,further comprising means for supporting a portion of the upper and lowerhousings, said housing support means secured to the upper and lowerhousings.
 10. The apparatus of claim 8, wherein the upper valve housingcontains the resilient diaphragm.
 11. The apparatus of claim 10, whereinthe resilient diaphragm is an integral part of the upper valve housing.12. The apparatus of claim 8, wherein the upper valve housing and thelower valve housing are plastic.
 13. A plastic diaphragm valve apparatuscomprising: a plastic upper valve body, a resilient diaphragm and anactuator contained in the upper valve body; a plastic lower valve bodyconfigured to mate with the upper valve body, the lower valve bodyhaving an interior defining a fluid passage, the lower valve bodycomprising an integral weir, the weir configured to sealingly contactthe diaphragm; a weir support member extending longitudinally throughthe weir for reinforcing said weir; a support collar secured to both theupper housing and lower housing, the support collar engaged with theweir support member.
 14. The apparatus of claim 13, wherein the supportcollar comprises a U-shaped upper portion; and a U-shaped lower portion,the two portions overlapping and forming a closed loop and extendingaround the lower valve body.
 15. The apparatus of claim 13, wherein thesupport collar is constructed of stainless steel.
 16. The apparatus ofclaim 13, wherein the weir support further comprise a first and secondend and at least one of said first and second ends having a notchtherein for engaging with the support collar.